Some calls cannot reach us

We just had a switchover to Comcast business voice yesterday and ported numbers from our previous provider.  I thought all was fine, but my employer just tried to call from his house and he cannot get through.  No one is currently on the phones in our office, but when he calls, it just rings over and over for him but it never rings here at the office.  He can call other numbers in our organization and other cells and landlines.  But our main business number will not work.  Can someone please check on this?  Thank you.